Nervous system · Abdomen

Mesenteric and aortic plexuses !

The mesenteric plexuses are nerve networks on the aorta that follow its arteries to the intestines; they explain why early appendicitis hurts around the navel.

Official name: Superior mesenteric plexus

Opens in the Durgical app, no sign-up needed.

What it is

Autonomic nerve networks around the superior mesenteric artery and along the aorta.

What it does

Control the movement and secretions of the intestines.

Key facts

Roots

Superior mesenteric: lesser and least splanchnics (T10–T12) and vagus; intermesenteric/aortic and inferior mesenteric: lumbar splanchnics (L1–L2)

Moves

Sympathetic vasoconstriction and inhibition of gut motility; parasympathetic (vagus to midgut, pelvic splanchnics S2–S4 to hindgut) increases it

Feeling from

Visceral pain: midgut referred to periumbilical region (T10), hindgut to hypogastrium (L1)

Relations

Course

From the celiac plexus down the front and sides of the abdominal aorta, thickening around the superior and inferior mesenteric artery origins, to the aortic bifurcation where it becomes the superior hypogastric plexus

In front

Pancreas and the root of the small-bowel mesentery; the third part of the duodenum crosses in front of the aorta below the superior mesenteric artery

Behind

Abdominal aorta and the lumbar vertebral bodies

Lateral

Lumbar sympathetic trunks, which send lumbar splanchnic nerves into it; the inferior vena cava on the right

Below

The superior hypogastric plexus below the aortic bifurcation

How to find it

Seen in surgery as a web of fine nerve strands on the front of the aorta once the posterior peritoneum is opened, and as a dense nerve sheath around the origin of the superior mesenteric artery.

On imaging

Autonomic nerve networks are not seen on imaging. They surround the origins of the superior and inferior mesenteric arteries, so these vessels are the landmarks on CT and ultrasound. Their importance on imaging is indirect: CT shows a tumor, especially pancreatic cancer, encasing the mesenteric arteries or spreading along the soft tissue around them, which helps decide whether it can be removed.

Common problems

• Pain from pancreatic cancer can be eased by blocking it with an injection (celiac plexus block).

Clinical notes

• Retroperitoneal lymph node dissection for testicular cancer can cut these fibres and cause loss of ejaculation; nerve-sparing techniques preserve them
• High ligation of the inferior mesenteric artery in rectal cancer surgery puts the inferior mesenteric plexus and the hypogastric nerves at risk, with sexual and urinary dysfunction
• Perineural spread of pancreatic cancer along the superior mesenteric plexus is assessed on CT before surgery
• Hindgut pain is felt above the pubis (hypogastrium)

Related conditions

• Irritable bowel syndrome

Test yourself

Think of the answer, then tap the question to see it.

Add to my cards (4)

Educational information, not medical advice. For any symptom, see a health professional.

Its names

Official Latin (TA2)

plexus mesentericus superior; plexus intermesentericus; plexus aorticus abdominalis TA2 6705

Official Spanish (DeCS)

Plexos mesentérico superior, intermesentérico y aórtico abdominal

English (TA2)

Superior mesenteric plexus

Also called

plexus mesentericus cranialis

Sources: Terminologia Anatomica (TA2); Anatomy, Abdomen and Pelvis, Splanchnic Nerves; Anatomy, Abdomen and Pelvis, Nerves.

Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake

Send

Representative model, for educational purposes only.